Question

I have the following typedef function prototype:

typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);

I have no idea how to use it. I understand that (int, siginfo_t *, void*) is typedef-ed into sa_sigaction_t. But how would I use it? These are all return types with no variable names specified.

So I assume I want to create a variable: sa_sigaction_t handler. How would I use it? The syntax is quite confusing.

Thanks,

Answer 1

I understand that (int, siginfo_t , void) is typedef-ed into sa_sigaction_t.

Actually no. sa_sigaction_t is a pointer to a function that returns void and takes (int, siginfo_t *, void *) as parameters.

So if you have:

void foo(int, siginfo_t*, void*)
{
}

you can do:

sa_sigaction_t fooPtr = &foo;

and then call it like this:

fooPtr(0,NULL,NULL);